The Kokua Viewer had been updated to use the SL Viewer 3.7.5 and 3.7.6 code. Plus there are a bunch of fixes and feature additions. See: Kokua-3.7.6 is released.
There are Kokua versions that have the code to use the Server Side Appearance and Inventory API version 3 (AISv3) updates running in the RC regions and Sunshine RC Viewer. Those versions do not have RLV support. So, for this release you either get RLV or AISv3.
I haven’t used Kokua for some time. If you are using it, let us know how it is working. Imprudence used to be my preferred viewer for cross grid use.